Carlos continues: “We at EFACEC came across this theory and requested that INTEGRATED develop it into a software solution for inclusion in its programs. Weidmann carried out several research experiments to settle the oil curves, a group of decaying exponential E-field strength versus length curves that are accepted as almost the standard in the transformer industry. This empirical knowledge was developed initially by some power transformer manufacturers, and later, became public knowledge through technical papers published by Weidmann, a major supplier of pressboard to the power transformer industry. The oil dielectric strength is also much lower than that of the pressboard, so, in theory, if you can guarantee the dielectric strength of the weak oil, then the whole insulating structure will withstand the electric stress. The dielectric permittivity of the pressboard is twice that of the oil and so the electric field accumulates in the oil channels. The stratified insulation media is composed by pressboard barriers and oil channels. The weak link theory was adapted to the design of the insulating structures inside oil immersed power transformers. To do this, we at EFACEC employ simulation software to build virtual prototypes of the system prior to manufacture, to avoid wasting time on costly mistakes.”ĭespite using software simulation, a yet unsolved problem in the design of transformers came to light. In the current market, transformers need to be ever more effective and competitively priced.

This makes the design and manufacture of power transformers the core of EFACEC’s business. The director of Technology, Carlos Carvalho, leads a strong engineering team of 120 in the EFACEC Power Transformers Business Unit: “Our division has the capability to design and manufacture core and shell type power transformers up to 1,500 MVA and 525 kV, mobile substations up to 90 MVA, and immersed and dry type distribution transformers. The Group offers a comprehensive range of activities including Power Generation, Transmission and Distribution, Automation and Telecontrol Systems, Electric Mobility Power Supply Systems as well as Maintenance and Technical Assistance Services. The Group forms a complete value chain, from building turnkey projects to equipment manufacture, where integrated solutions are developed and designed in accordance with clients’ needs. The EFACEC Group is leading the supply of integrated solutions and equipment in the market of power generation, transmission and distribution.

Transformer design software